FIRST TIME IN MADRID (Madrid)

Hello,from tuesday 12 to saturday 16 I'll be in Madrid with another italian guy for the first time and I'd like to have some informations:- wich is the best option to arrive in the center from airport?- do you know somebody that rent a flat in Plaza Mayor area?- untill wich time will be possible to return with metro from Santiago Bernabeu, after Real Madrid - Juventus?- wich is the best Tapas bar in the center? And the best restaurant for domestic food?- wich are the best bars and discos in the center wednesday, thursday and friday evening?If somebody need some informations, I have visited EXPO 3 days ( Protected content ) untill now...